SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac00874d15cdb1643ae65a43a9be09fe6b450ebc5ab97fa0d16c9339f7767afd' 
  AND token = 'HIHLxTZVvD/OLNB/cvq/uujkILBqOJcoj6g+EpwhK5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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