SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab0cadb78431b2530b75a4150eaeb00188283f0113af7b5ffa97474ae362209d' 
  AND token = '49KFxSADVYV1wbZsKUSJO/RVSj+Rv6/QzIlpaQeBBAQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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