SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ed2bdd983f2c83e957ae9490be554e3a646dc1b6d639aa4406daf1f273451bb' 
  AND token = 'UWfvU0XfKb2fvEOZxjyR5GX2iw4TTRVqxNQ/apyFdkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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