SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2bca5289eb9933f83a24cce3cdda578e755d412d391dc3068781b1858b9d315' 
  AND token = 'NIIP69WnorqrqP3lYd6Fd9x2zw6bDTDIk41tbilbeWM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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