SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e07f5c6ad0313449c5a13c8a655fdfc13b523ed2ebba00709e3995b2a2c57a19' 
  AND token = 's2jNaEGzMdIZeQgfCcu/UpMo6yvf+/RB0iP9ZG84Ldw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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