SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8e874a71165d3055a4a49fab3a18cf08734ec89be9c130ddfcb334b77956f2d' 
  AND token = 'ip8YY+OobBnu9USdNF0OQ4N5vk9gnpYgxtfPf3hoODQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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