SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d8aa59fd220a89b92e857248af0b6fc5389b12db35a2f905025c122427307e4' 
  AND token = 'kk6AjXeX7WoGcZvprI6bfA4UedUCCzRfvHUcyCcnkQ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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