SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a249022227ef53c31477df7cdd6e695b8a30186ce06f2fc1e69ea4b3ca365f3' 
  AND token = 'aGhLY0cjBKdQtqUe75sSvika8NJMLkZgrZagSJsgGNA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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