SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e56ce1f965e469011daf6c5350832cd78047a414687c8d7195c341115930a66' 
  AND token = 'zZrm1zZ5TNn5m2wAa2qldwg0kjb3UNKDRaGbscSgQKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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