SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c0d317b58b8abadf686f8e8470c5fac215ac5340a85386681d6b91e5fadfb9a' 
  AND token = 'aquF+675HxDrjhzGgivqWOBLvpylDkpWw0WHg6Pu23Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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