SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '475afb23e0b524d692418386d53209eda3c201134aa15c879c0b6dd099ecd97f' 
  AND token = '24PCIdnu9bceuCxLYvP+IaejYiozyJY+BMAun4guQQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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