SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a244eef05e68f1202e540022c617481a91b44b77d861089066ec9f1ad05990fd' 
  AND token = 'VpzMGKdTWIBUv55hOOwouJ1iu7v8Xy8n3J59guQDWHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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