SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca24023988eee92a839cc9b6f12979f7bebc53ebffa0eb16e14c34cc718b2e00' 
  AND token = '2o6/IBsQSoo8mVxIIDsK/sIuuIJh4qWUdU7xBFwHMcY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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