SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3586a0100a3229b851536b727dbad7f4260d95a13f7215a76b5a527f511614e6' 
  AND token = 'kYwO9sEIGXmjoUdTcoD43xRvBdA+NHUShfrpHKHiw1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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