SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45eac78dd13997fcee546fb599fad32399bf4c32d8de815a96b2f09ace34c347' 
  AND token = 'AncsA1Y1vwS6qwop74KJvRDGvKfi/ikVmPzz9rgISIU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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