SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97d112f61645fa4568dbd226bbec91e73fd07078f1372ffee302af81bf3e371f' 
  AND token = 'WHPPoodfhHb3aoX50tYFlqSXJyVkTo8gkCZVF6pqb20=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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