SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7d96da4790100e001d5d1fc9d0b752bc63cfd57bc7746fd52caec24dc6dff4b' 
  AND token = 'arBhJYEjAGD3LuhrbvlNN+DkoVpZrns9boWsuw8y0EU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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