SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0212a1a9716e7ce33a854213ed5f8954b4645e1722f923dbf146be4fd238938b' 
  AND token = 'EV3X4z8fvMiulpBNJWaLQiK21va5KwcYBLHQZ6amjh4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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