SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49437635d84a586454b5fcaf8c08309c539b02610c2b8322c0665c7a943576ed' 
  AND token = 'b9HCi608U31qTZxJxJasM85VcbyfWC871L5Yp94CMbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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