SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b72ec8e2db2cc36e50368096ffecd41163661ef9d442e40a6beded210552bf9' 
  AND token = '7/6moLu3V3/awbriKUnfGPyDEvJEguokl4nia/4EAGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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