SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9039f82f0a168aade49a80e93ea3a392c92c6ab55f137bebc55d3e21aa20f1f' 
  AND token = 'Fqu1M0rEZecZEDPlOLDDayozxX3n6sqs/jwLwDO8/JA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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