SELECT 
  1 
FROM 
  q_lock_keys 
WHERE 
  key_id = '529b442c2304f47b03f058d55a475e20e87475a01b5a86481dae997327c448fe' 
  AND token = 'K5oqXgyAvtrBM3Q1YDfsuVmlC3zAwVrIMBjZ2BsnphQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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