SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e05341e8d9c69ae79adf26e326fadeae75030d6b2778596d873cfa83bc2ba5a' 
  AND token = 'zlA3+ZMj0oUeB94WrCs72yntGHQbpbs1HZF2eEbeMTM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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