SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99eb01f0f446d13e6ea95cf90a3f80187d65e70676e8fa03597d1597e933119f' 
  AND token = 'vxbZ0OZXB3h6taV+pJaXokjsUVXTAuh+Ubg/+5LkGBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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