SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3163388af31946cb22c6db0a5a61df5780b72adc8cc0744fa119b412e8e90c53' 
  AND token = 'SrtiNfrzNIRoMloOsj6pgGA6koPdlGztMnVX3veqFnY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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