SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a9c5fb3da3de550c1a3280f8eb44af2988835e35b00cad1894f258b0efaf7da' 
  AND token = 'uan4O4PGniR1hmZltLjXglubxVlyHndPJJFxMS9ZsSQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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