SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4c324f1ff298431871287150ac6416627c54b23648438864572330a7c43794d' 
  AND token = 'cfKcy+HfA+ofspCHUpQ7I6JOyz/ONB93xX/oRZZ+5DM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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