SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9c6415f5169fe0f4b35a9cefbdf3c75703d0dfd3767b782f456d8be97f60958' 
  AND token = 'YhvQRsQIiJod1mavqFKN4QPBGsXE4uGtP3XqtAbHMqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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