SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9d1c31924d9a1d9ab88946cfc6ffaadd6389d7b235795792aac20f1ff7ce7b1' 
  AND token = 'GaKk517ht1Gfnycy13Me2PrsmDzeXkdsMIDvk4wkOts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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