SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c44b1430ef8647521d877375fe619b44d7b8d727317c6f7567fa726c80946a36' 
  AND token = '9Z+V2k4qvXvRWaC69FuQvKo5/76sMythGkB+0H7GHzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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