SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '955d035a2dd6d9518830def61c5c276f31767e9216f22c63ffa3b30b58ed6a4a' 
  AND token = '1kYzN5/eT8MaAGryIYRuqgu1mVkwpaB6Ys2BgTvIZoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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