SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '966a342d19fdbb31109f692d0fd8b8e0626eeb737fb1fe76585887deaba7686a' 
  AND token = 'Qwx6ls2mdYojUIFnmWStAb0AJAEwOq0uDuK/5ewtvgs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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