SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6dbcfa95f787e24eb974071404591b753e6d480f9bbd0fe96d863d2217ea9e8d' 
  AND token = 'Kp62jSL6+t5fSjjdXH1O/gVGxnX88sS5ak8kKe48ma4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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