SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebbd34de83028af20632e7e365586f96ee1d78612ce726c3afa08748ec5735bc' 
  AND token = 'VqKcukzVES4bOTjGhWvWhu7/r9PT+Upx2Ax2NVE/dgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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