SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '443ce0bb232ffecd20065d3ad6fc92c39ef3cbdcfb4be53fcb02ebd8d2c80709' 
  AND token = 'NutUNcqbqo1UVtjsuLf21yQdg1QDPYDzxxmMe6M2PFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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