SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02e9d2379aecb3835f44cd3ce4b6415e9ea6ebfd8d40e405d437dc5383397c41' 
  AND token = 'gPD7bRUEvYIBAwEer9RasdKNQU7QN22bPAr543CYGj4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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