SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca20421f41930878e5cec9426cf25387656a528d78dc2f6921b4fb4cf2fb854d' 
  AND token = 'CZ9Lj6vZhaYMw4Dm/h6GbgU5bn6RSJyWQH7BbjhkpW0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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