SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '442687107724bb261150e34cada30b4f8bec34bc16387245804d0178068915a6' 
  AND token = '2NlLCzppQAtZOJQTHStjXRB2rs0xVrtPrTUIseeRamg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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