SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3231a15317f4901f89a9cebc8d38f0f587fa8a02abd46535b93ce429e9ad932b' 
  AND token = 'zJwOI7dK7v1fcGqjulFsugpxWwPulPWA/k4WzKjdK2c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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