SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'daf18d3eba0002b25d971375a68d6a03da238e0d04ed60e472eff7f203bba9d3' 
  AND token = 'tb3aNwjhMbnl0ddfheu9rKQLWBbv7k7jBxeEMiMnuqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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