SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24eb5d1ec6d592ef1121b7945f15dd8879b4ee13723eedf5f712372ad53407ae' 
  AND token = '6VuTdQ26yTBLHhpwVN6KuS4kRRl4W+nggVzv3JngPLQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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