SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1088a3452b38bdeb0fa763fa055ea6cb0872bef201e5cb98ecaa5a57b2341e03' 
  AND token = 'k+ywTKZyZjS0Iy2tYglOo1sj9boun2Fo+Ak5Qrhicf0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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