SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23519ba61ec591ccd9e462cf878ed20b81f85a32a8dc60c0a8031e45bfcd321c' 
  AND token = 'qX0iPQ5FS8zPdkITNTDIUo8ICSzt9dNdnY69Bhycdas=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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