SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ba2c335e08717acea08171350ad1ac6001dbaace2e34cb318d97b9e7dfeab5d' 
  AND token = '9KcFNouIpvPzvy9xKOVAXpC33vxUnSK79KL8IyTHkiM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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