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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac5f7f5d60e7ac35e4d4ff1fb87a347e017c937ca7d7d7df6b308fdfd78df2f0' 
  AND token = 'o9f845BY6QdkmEbLLmoVclO7KaUEmSoHRm5hxbY3Org=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}