SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2486af5f51eda5642aee56876ce306472ec58ceecda20a2f947cb1614729c025' 
  AND token = 'MMUw75WC5Ec9jS2xAKZJQoV9wRLVRMSbZur7Xym3kxw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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