SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f93404a40447860307fbdb8632e1b063369ba08922dc25768939cb477219402' 
  AND token = 'ZMSOM706XW51DNN+npXW8pUR0aXmHszARcjUcrcno/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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