SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6455be4215e066eb1abdfb313982062b7695f8b2694631f5ba60d52848790f6' 
  AND token = 'Q+WuhOM1sWh5iFM0fZpc/lEwv9ETZBsmijrx6T5W/QY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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