SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19e9109fce656bf99e2db34ba46616737fca11cca6a84f1dd2e99d794700f67a' 
  AND token = 'k9wepb2wEziQifxDZmK+GhDWn5D+7YO6D+HrjP6lF34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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