SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1720f0819c5908f4331f5d086214c614bd1b899bccabe2a4c114282df8da4bee' 
  AND token = 'JyYEKG7aKldXIEIvyT7sGVTN4LjC/4KR1Q11GxtRV5E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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