Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42d5349b5828080c2fa6044081fcff4a1c4f08f5aa9519c5d71be64ba5bd3e78' 
  AND token = 'OkGgN/YpwUgfzbQpJxwfCRtxmjQ3nDt15vAXwaErceM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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