SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00604d2c808b323dccbfe79ac68f79373f7677bfb18826248126d5929c18873d' 
  AND token = 'YjPnbrDjjG+fIz9AEEoW403bv4i+tDZthXZQW7eATRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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