SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2815840bb05d6a0cedc5977c4476c291507faaa7e7fbe4f061f40d7700e7cf9f' 
  AND token = 'zDqAksLRg4yd0gejofr7QXeyF6KYKC9WAbCHpV3DJIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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