SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c45b83a0f97762c27d5fdfc27cae0e5205148fddadd5e43df332bdd29238ff1' 
  AND token = 'Y4zipqdXT9gru2xQT6FocVi8dp4OqtRlMtPlWVIXgj0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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