SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97fa5520f654ab05e67c5789fb827437ba258a23064898ec893948f765348807' 
  AND token = 'kw+Ovt3pNcH540QGL5tTaOvcJCQLzPRuiLX9PYLA00U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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