SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6fafa5702332254650e639a3a0f68c4bf81c27e28f5de447ca7ab977f5651548' 
  AND token = 'HHh/r7fvrVMAbyzBP26dBGLq9O0vGHnKVDJ3dgFsiGQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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