SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3494fdc962c067716ea8ecce2858ff209527bc1cfb81ac6ee426549c699194a4' 
  AND token = 'BCrVRBEcRdDuF9iEWFS0MfpqoQCITrMLr3gkTdqSADk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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