SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b50ad148086b7965fda0e9101b7ad13f68c37bf39ae920b02fb828077cc4987e' 
  AND token = 'QigyQRJrsnHsvq/CX+/au1dCmg27hHlYNgklRd+WT7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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