SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7930803e90d71f97b91cc683dbd1db51f9d7bac4f7fe926edc5f26e58cdbd327' 
  AND token = 'Sp36tMC3lSEfCtwzP7ptfhoaCxlTeko+JLDx03LVOpI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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