SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df7ae286d57bf95ba28c225a31b6cb144784e208edfc5cea8e2537cc0496669f' 
  AND token = 'Fsp/E+xtKD7MXsI6fjwM1yH4wJGJu9Hdu2YyyEvo7Cw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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