SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1efab6dfacd3c6b41987d4a19ac1fb14751c288e5e9513e4ae1e4deb5f4ef09b' 
  AND token = 'I1+gdZXuDebSAZpr3dXb9c8G0B5tdkLWi+7joeyPvGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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