SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '669de6753fe1bb0c8d15d856366811b31a23b54135c258698ecf03371f6c26ac' 
  AND token = 'cwVpfzVLpKGJF0XDxYIq1PXFhfXjr3NrQ+Ah+IZrYBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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