SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f47fe785921762ddbcc19866271ae2d1300baa903e7e1fa5ce804b76f3a3d338' 
  AND token = 'Fy9P05vckj/nz+MpPsjP2Y+I+vpF/u3z0vTonsQRsjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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