SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4387dc98d8a76a894238ec0258c421c44f9dfe0a113e2fbeaa3e26a2283b163e' 
  AND token = 'c5bsdGNMirrR95JvaYH6tPXhUAE5gTJDYtRA0F8SHLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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