SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fa3f7673fd13ed25f58a94725fa2559869c64c4b3228adbdbfa3ee534db5a96' 
  AND token = 'axPOJTxPkAuEABmMbBjNpCWso/1A7jj+xTXwEezgf/k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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