SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36e2390f347f528a942d00f44fd6aa11d1d2ec990aecee4d0929fa9a4f07ce1e' 
  AND token = 'AzsjfZhOgRd5FlfgW8SDk0GOw1vb2nUMT7KDL1Lb8m4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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