SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c61f2b837534810a0bfa3c04141d8c6746fa514a0b7ab09e5cea8199ee86e0db' 
  AND token = 'PnJN4rqIF/BHKUz/GSMlSM3YILD6hZCf2n4i606gEwU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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