SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0894d993f22ac4196d4acdb7d07d4eb9d1079887e5f5f8d7c5c6c86df6bd5e0' 
  AND token = '28QjahL7xKJ+IKAuh8JSYrjBzh5GY/l90UFTOZ3LQB8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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