SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30b59eb6b16851118d681f810068b1b6f7c04df0b821f4d22806616ab247517c' 
  AND token = '7KKzjXh2v09ikKj/bLwCpDg3TQ8mK189uc/kQV2wbgs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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