SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97218ff6440a71791de7a154bab30918ce26c5b1599b235f1a6a47333054495b' 
  AND token = 'UXOEMEv+CJvz/HbmgPx3+cHUOakVO9lKlQOBUuEQPwU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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