SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79169935585fd318e3a783ceed08d8fd18cc2ca48a48910449d75bd6c75d52e6' 
  AND token = 'hICVaZkXM4QSgr+Ho33KHiCLJgQlgGOfPgaAzPg0KHM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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