SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cf47eb52d630353c90d3b0971ed5924a97dd865fb1aa3258a08aaa499fbaa47' 
  AND token = 'NWfQ+86DeGNLyXKJkZCB7bcouK4GqirBLkQ1CtwhvQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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