SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d91b3590a51732e90d98264c7ec68df318a5e051d3184d29935fd51e7b57db9' 
  AND token = '94ThpVxhU8ygr1HQT6rZxaqoolvmQE6Fq57woF1O6lg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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