SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4acb0ee4976bfa0406cfd82c2623e5e15a553b20863cff5f54d9863749d5e8cc' 
  AND token = 'uwM06+wcTCyzUc3cWNDoQIeQneNJNGIxFb11vZt8924=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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