SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87942e3b3e12a4885962ae0fbf36942782e94bb4d3d831f751258f0b84a4cbf4' 
  AND token = 'YNyRye7Vw0gGV+EGNcjZOGA+rvf/ytfVoVRypteuo9k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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