SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e9acecf894986e096dfaba8dd0b0f3ad90ef2ccff28426c55bb9f17efb56753' 
  AND token = 'u7wZOGiMygziVKvVeznuBmuby0A17qYoBnhxEViqUoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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