SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd2750c4ace2b1ce5d62866ae2076636cf5842aa781750747a566166f9b2e898' 
  AND token = 'lWVWJRI7p+gxu9oJ4Ookq5NEwR9F3wHQElxCXu+Uzyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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