SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6b4b54141d0f196b901648ba791840cb2ccfd1c83dc5e9ae67cd2896a37d8a1' 
  AND token = 'bhzbLvaK2ZA27QMSaoYeLmEWgXSkNynIlfgBNh+75vY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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