SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8c12935e120c6f6a8407e59e219d1b0fa71f3faa63577034249a8b0407a8d6f' 
  AND token = 'Wwqbih5yBFxBh/eFjfkOC8poTEv+3iwI05wQ3GHqKkA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00063

JSON explain

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