SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36a0b15bfdfd874ffbe4e6610c9976f44385b0cabd749b61f632abae2d29b65b' 
  AND token = 'Kw/Iz66AHPi2OE96BNtGOo0NotiDbSWDbNThDsrBWzM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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