SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e64c7a94184e1f60cfd6fda184a658f9bb048aa8c33e3a439d9527896b0c5e2f' 
  AND token = 'NzyZL730gnarXGcQrLyoSkA4Oz7+YKbjPN0lZ2ORrrk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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