SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'decb2d0e148162f1b502f737dcbbe70a20b0d6910150798208181bf6f1c0b6f4' 
  AND token = 'cso97uSYMR8OhePc70hkDzTQAleeNZyOW8mJi/47kS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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