SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba4388a43e81cba3543fdfb1586c9cb3a3d44880c3a4bad613df0e9e4031624e' 
  AND token = 'XfhdzpVLHXrgMJ86U+j1bEogcGTCIwtV8NzztFINw/k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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