SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df72d04d2ee687a01fdd70f0e8ef58181913c403d0baeaea195b1f84281eb51c' 
  AND token = 'FWypupJ40zRAebDWjciqpABgPuGWH66x8OMGQDZHFaI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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