SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb7b6fe72d4748fb9f314cb342ea6e7fd01e2d936cce39bb1b6af8eacb36101a' 
  AND token = 'Qzg8JKVCTXk4OQhGAyyQXv7FD+yoMBWSlfZIv6rXzqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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