SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd816e3742941f3b62c774e1ca28b8358be64ae62404c812308c0180c5969ec0d' 
  AND token = '64wQF2ENEbQck1Nr66RihftcD0uFVuQpo+i5ncEj3tM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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