SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c36547eaead92e1786451ba080388da5417f09f7ebbbf34150b430677b483617' 
  AND token = '2jBKmxe/W7R2qFOPjaM8f2E6qNDEMxOz/HaNSXKJ9pw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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