SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4669cfd15feb4cf559120e3a46ccc9278c28f0d06aa3de1ff9afa0d855741c1b' 
  AND token = 'wHx39imuFghXqA1QtuSTsGriTjk7yVyyBJJXeDdQMkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}