SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10f037968911575b5de028ed5fbfb02a75e9a9c957dacc0132ddde45d310dbc7' 
  AND token = 'BT9NtffvtmQECCKWvoeStfpIQOtDYM1zwHTieeeuqOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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