SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5048d2644eae4785cfefd2009102b55a01afd83d95a016d1bf7441164ea436ac' 
  AND token = 'pX/TLj6n+dURSjOtqgoe+oVbr5hvhCLcXKUWPmGNtQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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