SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bccf79659b7beb9fd16230045fb7be7e35361f9cbfca06a185d7cb62dd6f792' 
  AND token = 'Y46MQv+cPTfUf9BAXWDGymxek4wRwtpTIzq+iCxa2JI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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