SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dafc0e1443162a3588f38673bd0b18f51732d9dfb55cf0088415c7033ad0b0b3' 
  AND token = '9omtZ+DgMqhZ7fwETPuUpq+5V7k78HZ6S3t6DHEOAww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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