SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '116898ac844e087ebb228cc767f63786cdd978b98dc26aa8ee50a06415909d90' 
  AND token = 'VxczxmYEYk33K81L2u0CSHYIewntvCn3KINuVes5aD4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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