SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ed0d627ed4b06905f7b43f5dbcfae65f44c36b5f3658f3587069a452c391180' 
  AND token = 'GwcbVFx6Lzf08JvHvM9RGkzfJ4MqT/sOQKPh+uKmuDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}