SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3841648a43a32100dafeefb855d46b515e88b721f3cadd975c01fd0fe304819' 
  AND token = 'gEl/ejMtdxVU2U60UUXDi/F7ZlExWwkccQfPGAdskcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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