SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3696536d96409e76f66c7e88fb16f1b5806609a816b0c6d2885ab59c705ca0fd' 
  AND token = 'IQzUbsINvAjrxGA1KdAH6oMgdmogcPjhAc8M2gkvCTc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}