SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a94a62c558f9e00688fd4928f9ec8ad8df78f771124295fb8e7b083334f52b73' 
  AND token = 'IDUxbtJ0uQvVyjInNbSVk9sIrGLIkH+9+VKGcQrWaME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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