SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33d6e1025f146e382fa2274d54d9e3a917b96d4ffa3e14709419a2b8ca055884' 
  AND token = 'dhWvHnOmEbmgixvW+Ys87ChjUIwKeptW12Cu1GA4rBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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