SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93cc83bbaae40e1e5275d09ff8d403c9f32291cafe709fdda89681a8bea29420' 
  AND token = 'eVJ+Z1cl+CPV6HJplEpQOsLYXfXHTukOWh6Oam7EgII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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