SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f740d812531086cea2c909f906270142dc1d6bdeb6cad0470aa891b8261f3ba6' 
  AND token = 'Z3m85jFnjFk3QlFPrHMwZ2MFDc4A9LNZruW3fR0FEVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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