SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '422143e96f493b11942b221896e22229ddf5002009d8d752a8915d081a4d92a5' 
  AND token = 'gpG0e/FdErpjWneLvEeV4ZYLGPTJvGDbmp6MMuqysC4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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